1. Field of the Invention
The present invention relates to a method and an apparatus in a glass sheet bending furnace for preventing the deflection of a mould wagon bearing rail as the mould wagon is carried along a conveyor track, consisting of rollers upon which the bearing rails are resting, the furnace including a top array of successive heating sections and a bottom array of successive cooling sections.
2. Description of the Prior Art
A problem encountered in a glass sheet bending furnace is the considerable deflection of the bearing rails mounted alongside a mould wagon during a cooling cycle. The resulting deflection remains in the rails even as the wagon is advancing along the top track from one heating section to the next. The deflection of bearing rails results in a shaking or "jolting" movement of the wagon which is why especially rather large glass sheets are easily broken even before a bending section on the top track.
The deflection of wagon bearing rails occurs on the bottom track as a result of temperature differences. First of all, the hot bearing rails deliver heat through their bottom surfaces to conveyor track supporting rollers. Secondly, the hot glass and mould deliver radiation heat to the top surface of a bearing rail.